In response, Air Berlin CEO Thomas Winkelmann accused pilots of "playing with fire".
Lufthansa's low-priced division Eurowings - which is wet-leasing Airbus A320-family jets from Air Berlin - has been affected.
Berlin's Tegel airport and Düsseldorf airport, Air Berlin's hubs, were hit hard by the strike action, which also affects 42 planes run by Air Berlin on behalf of Eurowings and Austrian Airlines.
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On Sunday his company Intro offered 50 million euros immediately for the stricken airline, with up to 450 million euros of further payments "depending on performance", he said.
After losing the lifeline of regular cash infusions from Gulf carrier Etihad in June, Air Berlin filed for insolvency on August 15. "That is crucial in order to bring talks with investors to a successful conclusion", Chief Operations Officer Oliver Iffert said in an internal memo.
The airline had long struggled for survival, and booked losses amounting to 1.2 billion euros ($1.4 billion) over the past two years.
On Air Berlin's website, they cited "operative reasons" for the cancellations on Tuesday, and asked passengers to call a helpline and refrain from travelling to the affected airports. "That's the only way we can secure as many jobs as possible".
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Air Berlin announced on Monday that it would end its flights to the Caribbean from Düsseldorf beginning September 24.
The financial support given by the German Government will keep Air Berlin flying for 90 days.
Germany's giant services sector union Verdi on Tuesday expressed solidarity with the absent pilots.
Air Berlin is Germany's second largest airline and employs over 8,000 staff.
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While developers had access to beta versions of the new software since WWDC, Apple didn't make it part of the public beta program. There is also elevated heart rate detection which alerts you when you are at rest but your heartbeat is up.